Since you are looking at "ancient civilizations," you will need to look at (specifically) the history of Egypt during the time period you are studying.
Look at the rulership and how it progressed. Was there a smooth transition between rulers? Did one ruler rule the people with compassion while another with autocratic dismissal of the population? Also look at the general economy (if that information is available) of the country. If those stats are not available, then look at general reports such as famines or wars that engulfed the country. You will find that wars and famine have disruptive effects on the population and the governing of ANY country.
So... that's my advice as to where you should START. Best wishes!
